Wu zhuang yuan (1980)

A dying Manchu Kung Fu fighter sends his three sons on a mission of revenge against the five Southern champs who defeated him a generation ago. The Manchus beat down the families but one son, Billy, takes a crash course in both North and South Eagle styles as well as Horsehead Fist. Only then, is he able to confront each of the three Manchu fighters in a martial arts finale like no other!